Process of transforming carbon dyes.



NITED STATES ATENT Genres.

HERMANN GUTZKOWV AND BENNO HOMOLKA, OF FRANKFORT-ON-THE-MAIN, GERMANY.ASSIGNORS TO THE FARBW'ERKE, VORMALS MEISTER, LUCIUS & BRIINING, OFI-IUCI-IST-ON-THEMAIN, GERMANY.

PROCESS OF TRANSFORMING CARBON DYES.

SPECIFICATION formingpart of Letters Patent No. 661.800, dated November13, 1900.

Application filed February 15, 1900. Serial ITO-5,300. (Specimensd Toall whom, it may concern: stuffs of these two groups are transformed byBe it known that we, HERMANN GUTZKOW, the action of said bases intoproductsinsolua citizen of the Empire of Germany, and ble or almostinsoluble in water, which, as BENNo HOMOLKA, Ph. D., acitizen of theElIlfar as they are derived from congo colors,

pire of Austria-Hungary, both residing in possess no longer or onlyslightly the great Frankfort-on-the-Main, Germany, have insensibility ofthe latter to acids. From this ventcd certain new and usefullmprovementsit follows that the dyes obtained with the in the Manufacture ofTransformation Prodtransformed dyestuffs of the last two groups nets ofCoal-Tar Colors, of which the followare much faster to water and whenemployl0 ing is a specification. ing congo colors remarkably faster toacids We have found that those aromatic bases in general. which containin the molecule once or more The practical application of our method isthe bivalent group NHOH or NR- very simple. It consists in treating thedye- Cl-I (wherein R means alkyl) linked on both stuff to betransformedwit-h the aqueous so- [5 sides to benzene (toluene or Xylene)act in a lution of any salt (hydrochlorid, sulfate, the.)

peculiar manner upon agreat number of coalof any of the said bases at amoderately -eletar dyestuffs which contain primary or sec vatedtemperature. (With some dyestuffs ondary amido or hydroxyl groups. Asbases the transformation takes place when left of this kind we haverecognized: I. Orthostanding more orless atindoor temperature.)

20 amidobenzylanilin, para-amidobenzylanilin, The following exampleswill illustrate the and their homologues and nit-rogen-alkylatedprocess: derivatives; II. Anhydro-para-amidobenzyl Example IBenzal"violet (Dc'ibneWs rioalcohol and its homologues and nitrogen-al-Zet).Thirty-two parts by weight of benzal kylatedderivatives. Thetransformations of violet are dissolved in water, to which is 25 thedyestuffs produced by the said bases are added the aqueous solution of asalt of one of different kinds. In the first place they of the saidbases-for instance, fifty parts of are affected by the class ofdyestuffs to be emthe hydrochlorid of ortho-amido-meta-xylylployed, andin the second place they depend. para-toluidin or the equivalentquantity of upon the choice of the transforming base. the hydrochloridof para-amidobenzylanilin 30 The basic dyestuffs soluble in water of theor the hydrochlorid of monomethyl paradiamidotriphenylmethane,triamidotripheamidobenzyl alcohol, &c. On allowing the nylmethane,safranin, and rhodamin groups Whole to stand for a little while atindoor are transformed by the action of said bases temperature or onheating it for a little time into new products, likewise soluble inwater, to from 60 to 70 the violet color of the so- 35 which differgreatly in shade from the origilution becomes a beautiful green-blue.The ual dyestuffs. Thus, for instance, from the dyestuff is then salted,filtered, pressed, and bases of groups I and II from the diamidodried.Thus a brown-Violet powder of metaltriphenylcarbinol (called benzalviolet or he luster is obtained, soluble in water and Dolmers violet)blue to blue-green, from alcohol with a green-blue color. Most of the 40fuchsin violet, and from safranin and rhodyestuffs transformed by theabove-men- 9o damin 6G red-violet dyestuffs are obtained. tioned basesexhibit a characteristic behavior The transformation, however, showsitself in toward nitrous acid. In a similar way does quite a differentmanner with the dyestuds the dyestuff just described. If its alcoholicof the fiuorescin group and with certain azo solution, slightlyacidified, be treated with 5 dyestuffs, the socalled congo colors. Insodium nitrite, then the solution becomes the case of these two groupsof dyestuds the green, while a similarly-treated solution oftransformation of the shade produced by the benzal violet dyes, as isknown, slight-1y yelaction of the bases mentioned at the beginlow. Theproducts of transformation of the ning is more or less important, butthat of benzal violet thus obtained dye cotton morzo other propertiesvery efficacious. The dyedanted with tannin blueto blue-green shades.Ioo

Example II Fuchsia. Thirty seven parts of fuchsin treated with, forinstance, forty-seven parts of the hydrochlorid ofmonomethyl-para-amidobenzyl alcohol in the m anner described in ExampleI yield a dyestuff in form of a powder of bronze-like luster, which issoluble in water and alcohol with a violet color, dyeing cottonmordanted with tannin violet. Its alcoholic solution, slightlyacidified, becomes blue when treated with nitrite. If, however, onlysixteen parts of the above-mentioned hydrochlorid base be used withthirty-seven parts of fuchsin, then a product is obtained which issoluble in water with a redder less violet color. Rhodamin 6G is readilytransformed into a blue-red dyestuif when treated with the salts of theabove-named bases, even when allowed to stand at ordinary indoortemperature.

Example III- Congo c0l0rs.As congo dyestuffs we understand here thosesubstantive cotton dyestuffs which are obtained or supposed to beobtained by the action of tetrazodiphenyl, tetrazoditolyl,and similartetrazo compounds with two nuclei upon aromatic amins, polyamins,phenols, polyphenols, and

amidophenols of the anilin and naphthaleneseries, as well as theirsulfonic and carboxylic acids. These dyestuffs are transformed, asalready stated, by the action of the bases mentioned at the beginninginto insoluble products of great value in the manufacture of lake colorsand paper-printing. The following examples will illustrate both methods:

Eocample 1-O'0ng0 retl-Thirty-five parts of congo red are dissolved inthree thousand five hundred parts water, to which are added 15.5 partsof the hydrochlorid of mono-methylpara-amido-benzyl alcohol (obtained bythe action of formaldehyde upon the hydrochlorid of monomethylanilin)dissolved in a little water. The mixture is then heated on thewater-bath, when the new product separates as a red precipitate. It isthen filtered, pressed, and dried.

Example 2Be'nz0purparlne 4B. Thirtyseven parts of benzopurpurine 4B aredissolved in about three thousand seven hundred parts of water, to whichare added seventeen parts of the salt of the base obtained by thereciprocal action of molecular quantities of xylidin, formaldehyde, andhydrochloric acid. (It is quite immaterial which xylidin is chosen, itbeing best to use the technical xylidin, being, as is known, a mixturechiefly of as-m-xylidin, para-xylidin, and small quantities of otherxylidins.) The whole is heated for a little while on the water-bath, andthe precipitate thus obtained is then filtered, washed, and dried.

Example 1-Dlamln scarlet 3B.Thirteen parts of diamin scarlet 3B aredissolved in two thousand parts of water, to which is added the solutionof a salt of one of the said basesfor instance, five parts ofanhydropara amido-meta-tolylalcohol. The whole is heated for a shorttime at gentle water-bath temperature, when the product of reactionseparates as a bluish-red precipitate hardly soluble in water. It isthen filtered, pressed, and dried.

Ema-mple I VE laorescln clyeslufis-What has been said concerning thecongo colors holds good also with regard to the application of productsobtained from the fluorescin dyestuffs by theaction oftheabove-mentioned bases. The products, as already stated, areinsoluble, and thus particularly suited for the production of lakecolors. The process is illustrated by the following exam ple:

Example 3E0sln.-Twenty parts of'eosin are dissolved in about onethousand parts of water, to which is added one of the bases mentioned atthe beginning--such, for instance, as four parts of such a base as isobtained either by the reciprocal action of molecular quantities offormaldehyde and technical Xylidinthat is to say, mixtures of isomericortho-paraand m etaxylidins-in presence of acids or by the transformingaction of mineral acids upon anhydroformaldehydexylidin (obtained fromthe same technical mixture of the isomeric xylidins) in the form of asalt dissolved in water. The whole is then gently heated at waterbathtemperature, when the new product separates as an ardentred precipitatehardly soluble in water.

We have tested in a similar way a long series of coal-tar colors as totheir behavior toward the bases mentioned at the beginning. In everycase the above-cited fact was confirmed, that the choice of thetransformingbase is almost immaterial upon the result obcule thebivalent group NH OH wherein the hydrogen atom of the group-NH-maybesubstituted by alkyls, linked on both sides to aromatic carbon atoms,substantially as set forth. 7 I

In testimony that we'claim'the foregoing as our invention we have signedour names in presence of two subscribing witnesses.

HERMANN eUTZKow.

BENNO HOMOLKA.

/ Witnesses:

HEINRICH HAHN, ALFRED BRISBOIS.

